1. Field of the Invention
This invention pertains generally to ultrasonic diagnostic techniques, and more particularly to a method for assessing vascular architecture using ultrasound and displaying the vascular architecture in three dimensions to locate and identify tumors.
2. Description of the Background Art
Diagnostic ultrasonic techniques in medicine are of growing importance, because they are non-invasive, non-ionizing, and of low cost as compared to other sensing and imaging methods. As a result, ultrasound has been identified as a preferred non-invasive diagnostic tool for assessing the architecture of the vascular system in a human body for various medical purposes and, in particular, for locating tumorous tissue. It is well known that most, if not all, tumors are associated with an abnormal amount and pattern of vascular development. Therefore, it is desirable to use ultrasound for assessing the vasculature in human tissue. However, current ultrasound systems are not sufficiently sensitive to measure minute changes in the vasculature which are indicative of early tumorous development.
As a result of the need for accurate vascular imaging and identification of tissue abnormalities, various solutions for more accurate imaging have been proposed. For example, U.S. Pat. No. 5,243,988 issued to Sieben et al. on Sep. 14, 1993, discloses an invasive, intravascular imaging apparatus and methods for use and manufacture, for imaging small coronary vessels. U.S. Pat. No. 5,233,994 issued to Shmulewitz on Aug. 10, 1993, discloses a method for detection of tissue abnormality through blood perfusion between normal and tumorous tissue. U.S. Pat. No. 4,932,415 issued to Angelsen et al. on Jun. 12, 1990, discloses a method of color coding two dimensional ultrasonic doppler velocity images of blood flow on a display. U.S. Pat. No. 4,580,574 issued to Gavish on Apr. 8, 1986 discloses a method and device for non-invasively monitoring the instantaneous fluctuations in the viscoelastic-related properties of a living tissue. U.S. Pat. No. 4,542,744 issued to Barnes et al. on Sep. 24, 1985, discloses a method and apparatus for remote tissue identification by statistical modeling and hypothesis testing of echo ultrasound signals. U.S. Pat. No. 4,276,885 issued to Tickner et al. on issued Jul. 7, 1987, discloses methods for enhancing ultrasonic images. U.S. Pat. No. 4,074,564 issued to Anderson on Feb. 21, 1978, discloses a reconstruction system and method for ultrasonic imaging. U.S. Pat. No. 3,771,355 issued to Sachs on Nov. 13, 1973, discloses an ultrasonic inspection and diagnosis system.
Still, however, current practices and methodologies in ultrasound assessment of vascular architecture are limited due to inadequate resolution and sensitivity of the equipment. In particular, color flow imaging, which provides spatial velocity estimates for blood flow, is currently curtailed by the conflicting requirements of spatial and temporal resolution.
Therefore, there is a need for a method for assessing and displaying the vascular architecture in the a human body using ultrasound which is accurate and easy to use. More particularly, there is a need for a method of ultrasound imaging of vasculature which overcomes current limitations, particularly in the are of color flow mapping. The present invention satisfies that need, as well as others, and overcomes the deficiencies found in devices and techniques heretofore developed.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention.